Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/08—Bellows; Connecting tubes ; Water traps; Patient circuits
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/08—Measuring devices for evaluating the respiratory organs
  • A61B5/083—Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
  • A61B5/0836—Measuring rate of CO2 production
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/08—Bellows; Connecting tubes ; Water traps; Patient circuits
  • A61M16/0816—Joints or connectors
  • A61M16/0841—Joints or connectors for sampling
  • A61M16/085—Gas sampling
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/04—Tracheal tubes
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/0003—Accessories therefor, e.g. sensors, vibrators, negative pressure
  • A61M2016/003—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter
  • A61M2016/0033—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical
  • A61M2016/0036—Accessories therefor, e.g. sensors, vibrators, negative pressure with a flowmeter electrical in the breathing tube and used in both inspiratory and expiratory phase
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. ventilators; Tracheal tubes
  • A61M16/10—Preparation of respiratory gases or vapours
  • A61M16/1005—Preparation of respiratory gases or vapours with O2 features or with parameter measurement
  • A61M2016/102—Measuring a parameter of the content of the delivered gas
  • A61M2016/103—Measuring a parameter of the content of the delivered gas the CO2 concentration
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2230/00—Measuring parameters of the user
  • A61M2230/40—Respiratory characteristics
  • A61M2230/43—Composition of exhalation
  • A61M2230/432—Composition of exhalation partial CO2 pressure (P-CO2)
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2240/00—Specially adapted for neonatal use

Definitions

• the invention relates to methods and devices for controlling fluid mixtures. More particularly, embodiments of the invention relate to methods and devices for preventing accumulation of gases that are normally eliminated by respiration, either spontaneous or artificial, at mainstream airflow or pressure sensors used in neonatal ventilators. Even more particularly, embodiments of the invention relate to the elimination of the so called dead space added by mainstream sensors used in neonatal ventilators to synchronize mechanical breaths with spontaneous inspiration and measure ventilation.
• Recent enhancements of conventional time-cycled pressure-limited neonatal ventilators include synchronization of mechanical breaths with the patient's inspiratory effort, ventilation monitoring, analysis of lung mechanics, and volume targeted ventilation. These enhancements involve the use of mainstream airflow or pressure sensors placed in line between an endotracheal tube (ETT) adapter and a ventilator circuit.
• ETT endotracheal tube
• Mainstream airflow sensors used in neonatal ventilators to synchronize mechanical breaths with spontaneous inspiration and measure ventilation can increase dead space, i.e. the volume added to the anatomic or artificial airway that does not contribute to gas exchange, and impair CO 2 elimination.
• the invention provides a device and method for dead space washout using controlled gas leakage.
• Particular embodiments of the invention provide a continuous gas leakage at an endotracheal tube (ETT) adapter to washout the airflow sensor and allow synchronization and ventilation monitoring without CO 2 rebreathing in preterm infants.
• ETT endotracheal tube
• Particular embodiments of the invention provide a device for removing waste fluid from a fluid supply and removal system that alternately supplies supply fluid to a user and receives the waste fluid from the user.
• the supply fluid and the waste fluid flow along a flow path, the supply fluid being supplied to and the waste fluid being received from the user by way of a supply tube.
• the system has a dead space.
• the device has a flow passage operatively associated with the supply tube and the dead space that directs the supply fluid and the waste fluid.
• An exhaust tube exhausts a portion of the waste fluid from the system and has a first end operatively associated with the flow passage.
• the exhaust tube is attached to the system at a location along the flow path between the user and the dead space.
• Other embodiments of the invention include a method of removing waste fluid from a fluid supply and removal system that alternately supplies supply fluid to a user and receives the waste fluid from the user.
• the supply fluid and the waste fluid flow along a flow path, the supply fluid being supplied to and the waste fluid being received from the user by way of a supply tube.
• the system has a dead space.
• the method comprises directing the supply fluid and the waste fluid in a flow passage operatively associated with the supply tube and the dead space and exhausting a portion of the waste fluid from the system through an exhaust tube.
• the exhaust tube has a first end operatively associated with the flow passage.
• the exhaust tube is attached to the system at a location along the flow path between the user and the dead space.
• FIG. 1 is a schematic representation of an ETT adapter continuous leakage technique and instrumental setup in accordance with exemplary embodiments of the invention
• Figure 2 is a schematic representation of an embodiment of the invention in which the exhaust tube is attached to the airflow sensor;
• Figure 3 a is a single-breath capnogram and V ⁇ recordings from an infant during intermittent mandatory ventilation (IMV);
• Figure 3b is a single-breath capnogram and V ⁇ recordings from an infant during synchronized intermittent mandatory ventilation (SIMV);
• Figure 3c is a single-breath capnogram and V T recordings from an infant during use of the invention (SEVIV+Leak);
• Figure 4a shows airflow and capnogram (delayed by 1.9 seconds) recordings from an infant during SIMV;
• Figure 4b shows airflow and capnogram (delayed by 1.9 seconds) recordings from an infant during use of the invention (SEVIV+Leak).
• VQ anatomical respiratory dead space
• V T tidal volume
• instrumental dead space further increases their V D V T ratio and can limit their ability to eliminate CO 2 , which may result in a higher arterial CO 2 tension, an increase in their central respiratory drive or lead to an increase in mechanical ventilatory support.
• a technique to prevent increased concentrations of CO 2 in the inspired gas due to airflow sensor dead space has been developed. This technique consists of a continuous washout of the sensor with fresh gas to clear the sensor of exhaled CO 2 by means of a continuous gas leakage at the ETT adapter.
• an exhaust tube 20 is attached to an ETT adapter 30 for leaking gas from the flow path of the system.
• Adapter 30 is placed between an airflow sensor 40 and an endotracheal tube 60.
• the airflow sensor is, in turn, attached to a ventilator circuit 50.
• the endotracheal tube is used to intermittently supply supply fluid to the user and channel waste fluid away from the user. While the endotracheal tube is used for both these fluids, it is noted that ideally only one of the fluids will occupy the endotracheal tube at a time.
• Figure 1 also shows a microcapnometer 70 attached to adapter 30 for recording particular gas properties.
• Figure 2 shows an alternate embodiment of the invention in which exhaust tube 20' is attached to a housing of airflow sensor 40.
• Exhaust tube 20, 20' can be, for example, a 15-millimeter long open-ended tube with a resistance of approximately 680 cm H 2 O per liter per second.
• Leakage flow is continuous during mechanical expiratory time and is determined by the positive end- expiratory pressure (PEEP). Leakage flow increases during mechanical inspiration due to a greater pressure gradient and is highest at peak inspiratory pressure (PIP).
• PIP positive end- expiratory pressure
• a PEEP of 4 cm H 2 O creates a leakage flow of approximately 0.35 liters per minute to clear a volume of 1.1 milliliters in 0.2 seconds.
• the open- ended tube resistance is sufficiently high to maintain PEEP and allow generation of PIP.
• An increase in ventilator bias flow may be helpful to generate the desired PIP when mechanical inspiratory time (IT) is short.
• the leakage flow adds to the flow measured by the sensor and can cause overestimation of the inspiratory flow and underestimation of the exhaled flow. These errors in flow measurement can be minimize
• the Babylog 8000 sensor, a hot wire anemometer, and the VIP Bird sensor, a variable orifice pneumotachograph have 1.1 and 1.2 milliliters internal volume, respectively. Ventilator settings of PIP, PEEP, IT and rate remained unchanged. Ventilator trigger sensitivity was set at maximum during SIMV and it was lowered to prevent auto-cycling during SEVIV+Leak.
• 0026 Non-invasive measurements of V T and respiratory rate (RR) were obtained by respiratory inductance plethysmography (Respitrace Plus, Sensormedics Corporation, Yorba Linda, CA) with two transducer bands wrapped around the rib cage and abdomen at the level of the nipples and umbilicus, respectively. Their relative volumetric expansion was determined by qualitative diagnostic calibration. Minute ventilation (V' E ) was calculated as the product of V T and RR.
• Airflow measurements were obtained from the VIP Bird' s pneumotachograph connected to a differential pressure transducer (Validyne Engineering, Northridge, CA) powered by a transducer amplifier (Gould Instrument Systems, Valley View, OH) or from the analog output of the Babylog 8000 during DVIV+Sensor, SIMV and SEVIV+Leak periods.
• TcPO 2 Transcutaneous O 2
• TcPCO 2 CO 2 tension
• SpO 2 Arterial oxygen saturation
• Fraction of inspired oxygen was measured by an oxygen analyzer (O2000, Maxtec, UT).
• All signals were digitized at 100Hz and recorded in a personal computer
• V T , V ' E , and RR measured by inductance plethysmography is reported in arbitrary units (AU), AU per minute and breaths per minute, respectively.
• birth weight was 835 ⁇ 244 grams and gestational age was 26 ⁇ 2 weeks.
• ventilatory support consisted of a mechanical rate of 21 ⁇ 6 breaths per minute, PIP
• End-inspiratory CO 2 concentration was significantly higher with the airflow sensor in place during the E IV+Sensor and SEVIV periods.
• the ETT adapter continuous leakage cleared most of the exhaled CO 2 from the airflow sensor during the SEVIV+Leak period and end-inspiratory CO 2 concentration remained within the range observed during the DVIV period without airflow sensor in place. (See Table 1).
• Ventilator trigger threshold was adjusted at initiation of the SEVIV+Leak period and no auto-cycling was observed. Ventilator measurements underestimated exhaled flow, V ⁇ and V' E in the presence of the ETT adapter continuous leakage. No differences in CO 2 rebreathing, TCPCO2 and V ⁇ were observed between infants grouped by ventilator model.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Pulmonology (AREA)
• Veterinary Medicine (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Engineering & Computer Science (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Emergency Medicine (AREA)
• Anesthesiology (AREA)
• Hematology (AREA)
• Physiology (AREA)
• Obesity (AREA)
• Physics & Mathematics (AREA)
• Biophysics (AREA)
• Pathology (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Surgery (AREA)
• Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
• Respiratory Apparatuses And Protective Means (AREA)
• Ventilation (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=23286897

Family Applications (1)

Country Status (6)

Families Citing this family (5)

Family Cites Families (9)

• 2002
  • 2002-10-18 EP EP02782175A patent/EP1441866A2/de not_active Withdrawn
  • 2002-10-18 WO PCT/US2002/033222 patent/WO2003033175A2/en not_active Ceased
  • 2002-10-18 JP JP2003535954A patent/JP2005506136A/ja not_active Withdrawn
  • 2002-10-18 CA CA002462722A patent/CA2462722A1/en not_active Abandoned
  • 2002-10-18 KR KR10-2004-7005455A patent/KR20040070339A/ko not_active Withdrawn
  • 2002-10-18 US US10/273,300 patent/US20030075178A1/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events